Bending machine



Oct. 10, 1950 E1, DE Wm 2,525,403

BENDING MACHINE Filed Sept. 17, 1947 s Sheets-Sheet 1 INVENTOR.

Oct. 10, 1950 I J, 5 w 2,525,403

SENDING MACHINE Filed Sept. 17, 1947 3 Sheets-Sheet 2 IN V EN TOR.

Edward JflaWuZ Oct. 10, 1950 I I 1, 13 wrr'r 2,525,403

BENDING MACHINE Filed Sept. 17, 1947 5 Sheets-Sheet 3 VII/M 1 74 INVENTOR.

' ZciwardJDeWZZi,

patented Oct. 10,

BENDING MACHINE Edward J. De Witt, Winnetka, 111., assignor to Wallace Supplies Manufacturing 00., Chicago, 111., a corporation of Illinois Application September 17, 1947, SerialNo. 774,568

Claims. (Cl. l5333 V This invention is concerned with improvements in bending machines for cold bending of metal members.

The general object of the invention is to provide a machine for bending ductile materials, such as metal rod or pipe, which machine is light, compact, flexible in use-and efiicient in operation and which is adjustable to permit bending large range of sizes of materials with a small number of adjustments or change of parts and with a minimum loss of time.

Another object of the invention is to provide an improved bending machine which will make any degree of bend on a given material up to 210 degrees withoutthe use of split dies or the like.

A more specific object of the invention is to provide a bending machine wherein the material to be bent is clamped to a shaped form which is movable between pivoted resistance blocks to initially bend the material around the form and wherein the resistance blocks are connected by a linkage which is controlled by movement of the form to bodily move the blocks toward the form and apply additional final bending forces to the material after the initial bending operation.

A still more specific object of the invention is to provide a bending machine comprising a ram actuated form around which the material to be bent is wrapped in the bending operation, and bodily movable resistance blocks against which the material is bent, the resistance blocks being connected .by linkage members, and a separable operating connection being provided between the linkage members and the form .for moving the blocks towards one another and towards the form upon movement of the form between the blocks whereby the material is bent around the form with minimum clearance and with minimum distortion of the material.

Another object of the invention is to provide in a machine of the type described a ram operated bending form and a material clamping member which is operatively connected with the form operating ram whereby the material is automatically clamped to the form upon initial movement of the ram prior to the movement of the form to begin the bending operation.

A further object of the invention is to provide in a machine of the type described a reciprocable bending form and movable resistance blocks which are mounted on supporting mechanism below the level of the material being bent whereby, a substantially clear flush top surface is provided where the work of bending the material isto be done and complete clearance in the bending plane is afiorded for greater flexibili-ty, better access and easier operation upon previously bent shapes and whereby right and left hand bends may be made without changing the .machine.

Another object of the invention is to provide in a bending machine of the type described swinging links connecting the resistance blocks which are adapted to be operated by the power ram whereby when the ram operated form has moved a predetermined distance during the bending operationthe links are actuated by further movement of the ram to bodily move the resistance blocks and wrap the bent tangents of the material around the form and thereby provide bends of more than 180 degrees.

Another object of the invention is to provide a bending machine having a reciprocating shaped form and movable resistance blocks wherein provision is made for adjusting the form and ,blocks to adapt the machine to different sizes of materials and wherein a novel form is provided to facilitate removal of the material after it is bent.

Another object of the invention is to provide a bending machine having a reciprocating shaped form and cooperating bodily movable resistance blocks wherein automatic controls are provided for repeatedoperation of the machine to provide duplicate bending operations.

These and other objects of the invention will be apparent to those skilled in this art from the description of the preferred form of the machine which is shown by way of illustration in the accompanying drawings, wherein:

Fig. l is a side elevation with-portions broken away of a bending machineembodying the principles of the invention;

Fig. 2 is a plan of the bending machine shown in .Fig. 1;

Fig. 3 is an end elevation of the bending machine;

Fig. 4 is a partial plan view illustrating the positionof the form and cooperating resistance blocks at the end of the bending operation;

Fig. 5 is a section on the line 5-5 of Fig. 4; and v Fig. 6 is a plan view of a piece of rod material which has been bent in the machine.

In the preferred form of the machine which is illustrated in the drawings a supporting frame or base comprising vertically arranged end channels or posts 10 and II supports a supply tank I2 for oil or, other suitable fluid for the hydraulic system. A driving motor I3 is mounted above the tank l2 and operatively connected by a drive shaft M to a pump which circulates the fiuid in the hydraulic system.

The motor [3 is electrically connected with a suitable power supply line and the necessary electrical apparatus is provided for controlling the operation of the same. The pump I5 is connected with a ram casing [6 by a suitable conventional 'fiuid circulating means or system. A reversing valve I1 is provided in the system for controlling the delivery of the fluid to the casing IS. The valve is operated by solenoids I8 which are supported on an auxiliary frame l9 extending rearwardly from the rear end post H] of the supporting frame.

The ram casing I6 is mounted at its forward end on a transverse block 26 which is secured by bolts or other suitable fastening means to the top of the rear end frame member I0. The block 20 is provided with a central aperture 2| for accommodating the ram 22 and preferably forms the end closure for the ram casing I6. The block 20 is connected by means of two parallel rod members 23 and 24 with a transverse mounting member 25 which is secured by suitable fastening means on the top of the end post II at the forward end of the machine. The parallel rods 23 and 24 provide a guiding and supporting means for a reciprocating block or carrying member 26 which is adapted to have secured on its top surface a shaped bending form 21.

The form supporting and carrying member 26 is provided with laterally spaced parallel bores 28 and 29 which receive the parallel guide rods 23 and 24 respectively, so that the member 26 may be freely reciprocated on the guide rods. A central bore 36 is provided in the rear portion of the member 25 for receiving the forward end of the ram 22 in freely sliding relation. A pair of laterally spaced ears 3| extend from the top forward portion of the member 28. A clamp supporting arm 32 is journaled between the ears 3|. One end 33 of the arm 32 extends downwardly and is pivotally connected by a toggle link 34 with the end of the ram '22. The other end 35 of the arm 32 extends upwardly and carriesa clamping plate 36 which is adapted to be moved upon operation of the ram 22 towards the bending form 21 to clamp the material to be bent to the bending form. The plate 36 is preferably provided with a concave groove 31 having a curvature approxi mately corresponding to the curvature of the surface of the material to be bent. The member 26 is provided on its top surface with a transverse upwardly projecting key or rib 38 which is re ceived in a groove 39 provided in the bottom surface of the bending form 21 to properly position the form 21 on the member26;

The form 21 is generally circular and is provided around its peripheral edge with a-concave groove 46. The groove 40 has a curvature approximately corresponding to the surface of the material which is to be bent. Arear portion of thev form 21 is cut away at 4| to facilitate removal of the material after the bending operation is completed. The topsurface" of the form 21 which may be recessed to reduce the weight, is provided with a forward aperture 42-for a threaded securing bolt 43 which issecured in the tapped hole 44 provided in the form supporting member 26. The form 21 is also provided with a vertical bore 45 for receiving an upwardly projecting pin 46.

A pair of laterally spaced resistance blocks or pressure dies 41 and 48 are mounted for coop eration with the bending form 21. The dies 41 and 48 are generally rectangular in shape and are provided with working edges or surfaces 49, 50 and 5|, 52, respectively, which are grooved to approximately correspond with the surface of the material to be bent. The dies 41 and 48 ar pivoted at 53 and 54 to the rear ends of a pair of supporting arms 55 and 56, respectively. The arms 55 and 56 are pivoted at their opposite ends at 51 and 58 to the front end cross member 25 and support the dies 41 and 48 in laterally swinging relation to each other.

The die supporting arms 55 and 56 are urged outwardly to move the dies 41 and 46 towards their outermost position by means of compression springs 59 and 66 which are mounted on rods 6| and 62, respectively. The rods 6| and 62 are each pivotally connected at one end to a rearwardly extending bracket 63 which is secured to the front end cross member 25 intermediate the pivot points 51 and 53. The other ends of the rods 6| and 62 are slidingly and pivotally connected at 64 and 65 to the supporting arms 55 and 56. The springs 59 and are fixed at their inner ends to the rods 6| and 62 and bear against the pivoted connections 64 and at their outer ends to constantly urge the pressure dies 41 and 48 outwardly.

The pressure dies 41 and 48 are also pivotally connected at 53 and 54 to the ends of a pair of toggle links 66 and 61 which extend inwardly and are pivotally connected to each other at 68. The toggle links 66 and 61 limit the outward movement of the dies 41 and 48. One or more additional pivot points 69 and 10 are provided on the toggle links 66 and '61 to permit variable positioning of the pressure dies 41 and 48 toward each other. The toggle links 66 and 61 carry at their pivotal connection 68 a vertically extending post 1| having a rearwardly directed abutment member 12 which is provided with a recess 13 for engagement with the upwardly projecting pin 46 of thebending form 21 when the ram 22 moves forwardly a predetermined distance in the bending operation (Fig. 4). The engagement of the abutment member 12 by the pin 46 operates the toggle links 65 and 61 and moves the dies 41 and 48 bodily inwardly towards the form 21 to bend the tangents of the material around the form.

Generally U-shaped horizontal side guards or work-supporting members 14 and 15 are provided' which are detachably secured at their ends 16, i1 and 18, 19 to. the end cross mem-v bers 29 and 25 on the main supporting frame and supported intermediate their ends by braces and 8| detachablyconnected to the top of the supply tank or other convenient portion of the supporting frame. The members 14 and 15 are adapted to provide a horizontal surface upon which the material to be bent is rested when it is initially positioned in the'machine.

The machine may be manually controlled for a single operation by push'button switches 82 conveniently located at the front of the machine. The switches 82 are connected by a conventional electrical circuit with the solenoids l8 and provide for starting, stopping and reversing the ram 22 to perform the bending operation.

Automatic operating of the machine to perform repeated bending operations is provided for by limit switches 83 and 8,4 which are mountedon the rear end frame member 19 and down: wardlyprojecting actuating pins 85 and 86 which the carrier bar 81.

The carrier bar 81 is secured at its forward end to a bracket 88 depending from the formsupporting block 2'6. The limit switches 83 and 84 are electrically connected to the solenoids l8 and control the operation of the valve [1. The actuating pins are movable on the carrier bar 8'! and may be adjusted to actuate the switches 83 and 84 so as to control or limit the movement of ram 22 in both directions.

The machine is operated in the following manner. A piece of material such as a metal rod or pipe Q8 (Figs. 4 and 6) is placed transversely of the machine with its ends resting on the members 14 and 15 and with the portion to be bent between the forward edge of the form 2'! and the clamp 36. The initial movement of the ram 22 operates the member 36, through link 34 and arm 32, to clamp the rod 90 in position in the groove 48 of the form 21. Continued movement of the ram 22 moves the form 21 forwardly and forces the laterally extending portions of the rod 90 against the working faces 49 and 5! of the resistance dies 41 and 48 which have been manually positioned, as in Fig. 1. The dies 4'! and 48 pivot or swing on the supporting members and 56 about the points 53 and 54 as the ram movement is continued and wrap or bend the rod 9|] around the form 21. When the center of the form 21 reaches a point approximately in the center line of the rod at the beginning of the bending action and the rod has been bent approximately 180 degrees the pin 46 engages in the recess l3 of the member 12 and actuates the toggle links 66 and BI to bodily move the resistance dies 41 and 48 towards each other and towards the form 21 to bend the tangents 9| and 92 of the rod 90 beyond 180 degrees. The relative size and adjustment of the form 21 and dies 4'! and 48 are such that without the bodily movement of the dies 41 and 48 which is effectedby the toggle links '66 and 67 th rod 88 would be bent 180 degrees with a minimum of clearance between the form 2'! and the dies 4? and 48. The effect of the toggle links 68 and 61 is to apply additional transverse bending forces to the tangents 9i and .92 of the material and thus obtain bends of greater than 180 degrees, particularly to compensate for resiliency in the metal. When the desired bending operation is completed the movement of the ram is reversed and the form 2? is retracted. The bent shape is then rotated around the form 27 until the cut away portion 4 4| permits its removal vertically from the form.

The bent shape illustrated in Fig. 6 maybe of material which due to its resiliency must be bent beyond 180 degrees so when it is removed from the machine the final bent shape will be the 180 degrees desired. 7

The machine may be adapted to bend different size materials by providing different size bending forms and resistance dies. The dies 41 and 48 are interchangeable. In the illustrated form the working surfaces 49, all and 58, 52 may be grooved for bending different sizes of material so that one set of resistance dies may be used for bending two difierent sizes or material. Any desired number of additional holes 89 and it may be provided in the toggle links 68 and 6? to receive the pivots 53 and 54 and to provide for varying the spacing between the dies 4? and 48. A form of the proper size may be provided for each adjustment of the dies 41 and 48. The resistance dies 41 and 48 may alsotake the form of grooved wheels.

While'specific details of construction have been referred'to in illustrating the preferred form of the bending machine, it will be understood that other details of construction may be resorted to within the spirit of the invention.

I claim '1. In a bending machine, laterally spaced pivotally mounted resistance blocks, mounting means for said resistance blocks, a shaped form, means mounting said form for movement between said blocks, means for moving said form, clamp means on said form for holding a piece of material to be bent against said form during the bending operation, and means connecting said clamp means to said form moving means whereby said clamp means is operated by said form moving means prior to movement of said form, said mounting means for said resistance blocks and for said form being positioned below the working level of the material being bent whereby to provide complete clearance in the bending plane.

2. In a bending machine, a supporting frame, spaced movable resistance members, a shaped "form movable in a path extending between said resistance members, mechanism on said supporting frame positioned below the working level of the material being bent for mounting said resistance members and said form whereby to provide clearance in the bending plane, means for moving said form relative to said resistance members, means for moving said resistance members toward one another and toward the form upon r movement of the form between said resistance members, clamp means on said form for holding a length of material to be bent between said clamp means and said form during the bending I operation, and means operated by said form moving means for actuating said clamp means.-

3. In a bending machine, spaced resistance blocks, a shaped form, means for reciprocating said form to move a length of material placed against said form between said resistance blocks and to bend the material around said form, a clamp mounted'on said form for securing the material in position thereon, and an operating linkage connecting said clamp with said form reciprocating means whereby when said form reciprocating means is operated the material will be clamped tosaid form and said form will thereafter be moved relative to said resistance blocks to perform the bending operation and when the bending operation is completed the material will be released by said clamp and the form will be retracted by return movement of said reciprocating means.

4. A machine for performing bending operations, comprising a supporting frame, a shaped form 'mounted for reciprocating movement on said frame, means for reciprocating said form, initially bodily spaced apart resistance blocks arranged to cooperate with said form to bend a length of material placed between said form and said resistance blocks, a pair of supporting arms pivoted at one end to said supporting frame and at the other end to said resistance blocks, a cross linkage connecting said resistance blocks, said cross linkage being foldable to move said resistance blocks bodily toward each other, and interengaging members arranged to provide a temporary connection between said form reciprocating means and said cross linkage when said form is reciprocated to move said material into bending engagement with said resistance blocks,

whereby said linkage is folded to move said resistance blocks toward each other to apply additional bending force to the material being bent as the form moves between said resistance blocks.

5. A machine for performing bending operations, comprising a supporting frame, a shaped form mounted for movement relative to said frame, a pair of initially spaced apart movably mounted resistance dies, 9. pair of initially extended tie links connecting said dies, said links being contractible to draw said dies bodily toward each other, power operated means connected with said form to move the same between said dies, and operating means on said form and said links to contract said links whereby to draw said dies toward each other and toward said form when said form has been moved a predetermined distance.

6. A bending machine comprising a supporting frame, a shaped form mounted for movement relative to said frame, a clamp mounted for movement toward said form for rigidly holding a piece of material to be bent against said form, resistance blocks movably mounted on said frame, a foldable linkage connecting said blocks and arranged when folded to move said resistance blocks toward each other, means slidably connected to said form and pivotally connected to said clamp for successively moving said clamp toward said form and said form toward said resistance blocks, and cooperating elements on said form and said linkage for folding said linkage to move said resistance blocks toward said form whereby, when said form and clamp moving means is operated, said material is first clamped to said form and then bent by movement against said resistance blocks and finally further bent by movement of said resistance blocks toward said form.

'7. A bending machine comprising spaced resistance members, a shaped form, means slidably connected to said form for reciprocating the same to move a piece of material placed against said form between said resistance members and bend the material around said form, a clamp swing ably mounted on said form for securing the material in position thereon, an arm extending from said clamp, and an operating link connecting said arm with said reciprocating means, whereby when said form reciprocating means is operated to move said form relative to said resistance members to perform the bending operation said clamp will be swung against said form to hold said material on said form, and when said form reciprocating means is operated to retract said form after the bending operation is completed said clamp will be swung away from said form to release said material.

8. In a bending machine, in combination initially spaced apart movable resistance members, a reciprocable shaped form, means for moving said form toward and away from said resistance members, a pair of initially extended link members connecting said resistance members to each other, cooperating interengaging elements on said link members and said form whereby said link members are contracted to bodily move said resistance members toward said form when said form is moved by said form moving means a predetermined distance toward said resistance members,

9. In a metal bending machine, a supporting frame, a shaped form mounted 0n said frame for movement relative thereto, a clamp mounted on said form for movement toward said form to rigidly hold a length of material to be bent against said form, a movable resistance block, a supporting arm on said frame,rsaid resistance block being pivotally mounted on said arm, a linkage pivotally connected to said resistance block, means connected to said form and said clamp for successively moving said clamp toward'said form and said form toward said resistance block, and interengageable members on said form and said linkage for moving said resistance block toward said form upon predetermined movement of said form toward said resistance block, whereby said material is first clamped to said form and then bent by relative movement of said form and said resistance block.

10. In a machine for performing bending operations, a recipro-cable frame adapted to receive different size bending forms, a pair of movable arm members, resistance blocks pivotally mounted on said arm members, a pair of initially extended foldable cross tie links connecting said resistance blocks, power means for reciprocating said form carrying frame, and interengaging abutment members on said frame and said tie links operating to bodily move said resistance blocks relative to said form carrying frame upon predetermined movement of said form carrying frame, said resistance blocks being adjustably connected with said tie links whereby the size of the bend may be varied by placing different size forms on the form carrying'frame and adjusting the resistance blocks relative to the tie links to'cooperate with the respective form.

EDWARD J. DE WITT.

7 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 411,071 Solter Sept. 17, 1889 1,319,608 Nelson Oct. 21, 1919 1,552,416 Bingham Sept. 8, 1925 1,899,280 Lidseen Feb. 28, 1933 1,948,474 Meyer Feb. 20, 1934 2,018,040 Sweeney Oct. 22, 1935 2,148,748 Hardy Feb. 28, 1939 2,153,935 Neukirch Apr. 11, 1939 2,277,519 Laxo Mar. 24, 1942 2,286,255 Brooks June 16, 1942 2,288,273 Enghauser June 30, 1942 2,405,931 Abramson Aug, 20, 1946 2,418,100 Stewart Mar. 25, 1947 FOREIGN PATENTS Number Country Date 1,306 Great Britain May 26, 1860 12,350 Great Britain May 19, 1897 2,482 Great Britain Jan. 30, 1902 

